/*
** $Id: lparser.h,v 1.57.1.1 2007/12/27 13:02:25 roberto Exp $
** Lua Parser
** See Copyright Notice in lua.h
*/

#ifndef lparser_h
#define lparser_h

#include "llimits.h"
#include "lobject.h"
#include "lzio.h"


/*
** Expression descriptor
*/

typedef enum
{
    VVOID,    /* no value */
    VNIL,
    VTRUE,
    VFALSE,
    VK,       /* info = index of constant in `k' */
    VKNUM,    /* nval = numerical value */
    VLOCAL,   /* info = local register */
    VUPVAL,       /* info = index of upvalue in `upvalues' */
    VGLOBAL,  /* info = index of table; aux = index of global name in `k' */
    VINDEXED, /* info = table register; aux = index register (or `k') */
    VJMP,     /* info = instruction pc */
    VRELOCABLE,   /* info = instruction pc */
    VNONRELOC,    /* info = result register */
    VCALL,    /* info = instruction pc */
    VVARARG   /* info = instruction pc */
} expkind;

typedef struct expdesc
{
    expkind k;
    union
    {
        struct
        {
            int info, aux;
        } s;
        lua_Number nval;
    } u;
    int t;  /* patch list of `exit when true' */
    int f;  /* patch list of `exit when false' */
} expdesc;


typedef struct upvaldesc
{
    lu_byte k;
    lu_byte info;
} upvaldesc;


struct BlockCnt;  /* defined in lparser.c */


/* state needed to generate code for a given function */
typedef struct FuncState
{
    Proto *f;  /* current function header */
    Table *h;  /* table to find (and reuse) elements in `k' */
    struct FuncState *prev;  /* enclosing function */
    struct LexState *ls;  /* lexical state */
    struct lua_State *L;  /* copy of the Lua state */
    struct BlockCnt *bl;  /* chain of current blocks */
    int pc;  /* next position to code (equivalent to `ncode') */
    int lasttarget;   /* `pc' of last `jump target' */
    int jpc;  /* list of pending jumps to `pc' */
    int freereg;  /* first free register */
    int nk;  /* number of elements in `k' */
    int np;  /* number of elements in `p' */
    short nlocvars;  /* number of elements in `locvars' */
    lu_byte nactvar;  /* number of active local variables */
    upvaldesc upvalues[LUAI_MAXUPVALUES];  /* upvalues */
    unsigned short actvar[LUAI_MAXVARS];  /* declared-variable stack */
} FuncState;


LUAI_FUNC Proto *luaY_parser(lua_State *L, ZIO *z, Mbuffer *buff,
                             const char *name);


#endif
